To execute a kill switch of "you are never allowed to run flash again" is far from fair, Adobe is the problem. However I will agree to differ; your work can die at the whim of a corporation.
And Adobe is still alive, as are others like IBM, Microsoft, and friends. On the other hand, SGI, DEC, Sybase, Novell, SCO, and tons of other companies are dead. And some companies, like HP, are technically alive, but all their product lines from that era are dead.
Getting burned once or twice is enough to understand that the organizational, political, and human sides tend to matter more than the technical. Older folks tend to chose stable, open solutions. Younger folks who haven't gone through that yet tend to chose technically glitzy solutions.